This application claims the priority of Korean Patent Application No. 2002-70063, filed on Nov. 12, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a spindle motor and a micro-drive apparatus including the spindle motor, and more particularly, to a spindle motor having a slim stator improved for use in mobile micro-drive apparatuses and a slim micro-drive apparatus comprising the slim spindle motor.
2. Description of the Related Art
FIG. 1 is a side cross-section of a spindle motor 10 in a conventional IBM micro-drive apparatus. Referring to FIG. 1, the conventional spindle motor 10 includes a hub 11, a magnet 13, and yokes 15. The hub 11 has ball bearings 17 in the space defined by the hub 11 and is rotatably supported by a base plate 19. The magnet 13 is fastened to the hub 11 to provide a magnetic force. The yokes 15 are arranged around the outer boundary of the magnet 13 and wound with coils and generate turning forces to the spindle motor 10 by interaction between current flowing in the coils and the magnetic force of the magnet 13. The yokes 15 are fixedly installed at the base plate 19.
Currently, most current mobile micro-drive apparatuses have a CompactFlash type I (CF-I) form, which is an existing flash memory standard and provides a thickness of 3.3 mm, and their application range is gradually extending. On the other hand, the conventional IBM micro-drive apparatus of FIG. 1 is excellent in terms of capacity, unit cost per storage capacity, and future competitiveness but adopts a CF-II form which provides a thickness of 5.0 mm because of the difficulties of making slim. As shown in FIG. 1, the conventional CF-II IBM micro-drive apparatus has the spindle motor 10 in which the magnet 13 and the yokes 15 are arranged to have the same central axis, thereby maximizing the rotation efficiency of the spindle motor 10. However, such an arrangement is not suitable for the CF-I form having a great demand. In particular, there is not enough space in which to install stator yokes because of the thickness of an actuator installed in the space where the stator yokes are to be located.